Continuation of study of the structure and functions of the basal ganglia is proposed. The basal ganglia have been a subject of longstanding scientific interest because diseases of these portions of the nervous syytems such as Parkinsonism, Huntington's chorea, athetosis, ballismus and torsion dystonia are major health problems. The comparative approach will be used. Basal ganglionic organization will be studied in birds, reptiles and mammals. Both the neuroanatomy and neurotransmitter distribution within the basal ganglia will be studied. Specific issues concern the relationship between the basal ganglia and the midbrain tectum, a visual system structure, and the organization of intratelencephalic pathways by which information is projected into the basal ganglionic system. These pathways are more easily studied in birds than in any other class of vertebrates. Neurobehavioral studies will also be conducted. These will involve measuring changes in metabolic activity of basal ganglia neurons while laboratory animals are performing orientation, turning and postural adjustment movements. Previous research indicates the basal ganglia play a major role in enabling animals to locate the body position in space and make locomotor and postural adjustments which change body orientation in space.